We (http://www.opencagedata.com) are sending such updates. Only 3-4 metrics, less blog articles and more open thinking about future plans, priorities, conferences we attend. 6-8 paragraphs. We ask for feedback but at the same time stress that it's optional.

We get praise for being open, honest, on-time (once per month) and even send updates if there isn't anything new.

We're self-funded so strictly we don't have to send anybody any updates (other than the tax office).